Electric incandescent lamp



Jan. 26, 1937. K SETOGUCHI 2,069,081

ELECTRI C INCANDESCENT LAMP Filed May 26, 1933 fAfI E'NT 47A KAZUU 5'5 Tam/5 1 H25 ATTURNEY Patented Jan. 26, 1937 ELECTRIC INCANDESCENT LAMP Kazuo Setoguchi, Tokyo, Japan, assignor to General Electric Company, a corporation of New York Application May 26, 1933, Serial No. 673,061 .In Japan May 31, 1932 5 Claims. (Cl. 176-4) My invention relates to-electric incandescent lamps and similar devices and more particularly to energy translation elements therefor having the form of ribbons or strips.

5 The object of my invention, is to provide a novel method for producing ribbon shaped energy translation elements which comprises wind-, ing a coil of filamentary wire and subsequently flattening or pressing the same into the shape of a ribbon, preferably by passing the coil between a pair of rollers. In a modified method, the coil is wound around a mandrel and compressed, together with the said mandrel. As compared with the present method which consists of rolling out a single wire of circular crpss-section, my method is much more easily performed and the finished ribbon has a rough surface, providing a greater active surface area.

Moreover, when used as a filament for an elec-- 20 tric incandescent lamp, the ribbon made according to my method is substantially free from deformation or sagging. Further features and advantages of my invention will appear from the following detailed description.

Inthe drawing, Fig. 1 is a diagrammatic representation of a method of producing a ribbon shaped energy translation element according to my invention; Fig. 2 is a diagrammatic representation of a modified method; and Fig. 3 so is an elevation of an electric incandescent lamp containing a filament comprising my invention.

- Referring to Fig. 1. a filamentary wire of refractory metal such as tungsten or molybdenum is wound into a coil l and preferably cut into lengths which are then passed between a pair of rollers ll-l2, causing-said coil to be flattened or pressed into a ribbon or strip II. The surface of said ribbon I3 is rough, due to 'the remaining visible traces of parallel lines formed by the individual turns of the coil. The ribbon i3 is substantially free from distortion even when operated at incandescence in an electric lamp due to the effects of the rolling operation which removes the cofling strains in coil Ill. The said coil I0 is preferably fed into the rollers ll-l2 in the direction of the axis thereof so that the turns overlap as they are pressed by said ollers, as shown in the drawing. In this manner a fiat ribbon ll of any desired thickness may be obtained easily by a singlepassage between the rollers.

In Fig. 3 is shown an electric incandescent lamp containing the ribbon type energy translation element or filament i3. Said filament I3 is mounted on leading-in wires l4 and sealed in. a bulb I5 having a base i6 mounted thereon.

' In a modified method, illustrated in Fig. 2, a. coil of wire I! is wound around a mandrel l8. The said coil 11, together with the mandrel iii, 10 is then passed between the rollers ll-l2 which flatten or compress the structure into the shape of a ribbon or strip I9. The individual turns of the coil in this case do not incline and overlap as in Fig. 1. The rollingoperation removes the 5 coiling strains eiiisting in the coil I0 and pr?)- duces a ribbon l9 which is twisted throughout its length and is substantially free from defamation even when operated at incandescence in a lamp.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. The method of producing an energy translation element for electric lamps and similar devices which comprises winding a. wire around a mandrel. to form a coil thereon and subsequently pressing said coil and mandrel into the shape of a ribbon. a

2. The method of producing an energy translation element for electric lamps and similar devices which comprises winding a wire around a mandrel to form a coil thereon and passing said coil and mandrel structure between a pair of rollers to press said structure into the shape of a ribbon.

. 3. A filament for electric lamps and; similar devices consisting of a, ribbon formed by compressing a coil of refractory metal and having a 

